Transmitter apparatus and transmitting method

ABSTRACT

The present invention is intended to realize a screen configuration according to a propagation environment and display capability by causing a server to transmit a plurality of pieces of screen configuration information describing a spatial arrangement of contents to a reception terminal and select, when the reception terminal receives a plurality of pieces of screen configuration information, screen configuration information and display the contents according to the propagation environment of the reception terminal and conditions such as display capability.

TECHNICAL FIELD

The present invention relates to a transmission apparatus andtransmission method which transmits contents including a media such asvideo, audio, text or still image and screen configuration informationfor displaying the contents.

BACKGROUND ART

As a method for integrating contents including text, still image, videoand audio, and describing their spatial and temporal arrangements, atechnology called “SMIL (Synchronized Multimedia Integration Language)”which is being standardized by the W3C (World Wide Web Consortium) iscurrently available.

SMIL is a description language similar to a hyper text descriptionlanguage HTML which is currently widely spread over the Internet and isa description language suitable for distribution of multi-media dataincluding video.

A description example of an SMIL file will be explained using FIG. 1.

Information from <layout> on the third line to </layout> on the eighthline of the description shown in FIG. 1 corresponds to information on aspatial layout of contents.

Information from <par> on the 11th line to </par> on the 16th linecorresponds to time information on reproduction of the contents.

Regions v, t and i in which video, text and still image are arranged aredefined from the fifth to seventh lines.

The 12th to 14th lines define time information on reproduction of thevideo, audio, text and still image respectively. “src=” included in the12th to 14th lines specifies a URL for acquiring the media and in thisexample, it specifies that video and audio are acquired using a RTSP(RealTime Streaming Protocol, Internet Draft RFC2326) protocol, whiletext and still image are acquired using an HTTP protocol.

Furthermore, “region=” included in the 12th or 14th, 15th line specifiesthe position at which the media is displayed and corresponds to theregions specified on the fifth to seventh lines.

For example, since the text data specified on the 14th line has regionid=“t”, the text data is displayed in the region specified on the sixthline.

The line number is given for convenience of explanation and is notdescribed in an actual SMIL file.

Next, the method whereby a client reproduces contents described in SMILsaved on a server over a network will be explained using FIG. 2.

A client 1604, a terminal which receives contents uses a protocol suchas HTTP to acquire an SMIL file describing contents from a server 1(1601) over a network such as the Internet. After acquiring the SMILfile, the client 1604 interprets the SMIL file and acquires variousmedia described therein, that is, text, still image, video, audio, etc.,from the server. More specifically, the client 1604 acquires video dataand audio data from the server 2 (1602) and acquires text data and stillimage data from the server 3 (1603).

Then, based on space information and time information described in theacquired SMIL file, the client 1604 reproduces the respective describedmedia at appropriate positions and appropriate times.

However, when contents are described using SMIL, the client 1604 cannotknow the type of the multi-media data described in the SMIL filebeforehand.

Furthermore, depending on the capability of reproducing the multi-mediadata of the client 1604, there is a possibility that all types of themulti-media data described in the SMIL file may not be decoded.

In order to solve this problem, a method whereby the client 1604acquires a decoder corresponding to the capability of reproducing themulti-media data is proposed (e.g., the method described in theUnexamined Japanese Patent Publication No. 2002-297538 (pp 10, 11, FIG.3)).

According to this method, even when the reception terminal does not havethe capability of reproducing the multi-media data specified by scenariodata of SMIL, etc., the reception terminal is allowed to acquire thedecoder as appropriate. This allows the reception terminal to decode allestimated types of multi-media data.

However, the above described media distribution method involves thefollowing problems.

The above described media distribution method does not take anytransmission state of the multi-media data into consideration at all.That is, no consideration is given to a case where the receptionterminal cannot receive the multi-media data.

Especially, when media are distributed through a radio transmissionpath, even if the reception terminal can decode the specified type ofmulti-media data, it may or may not be possible to transmit themulti-media data specified by SMIL depending on the band and error rateof the varying communication path.

For example, in a third-generation cellular phone system, a receptionterminal located far from a base station may be able to receive mediadata at a low bit rate, while a reception terminal located close to abase station may be able to receive media data at a high bit rate.

Therefore, in a radio environment, the transmission band of a receptionterminal varies according to the position of the reception terminal andthe type of contents that can be received also thereby varies.

For this reason, there is a problem that in a reception environment inwhich there is large deterioration of video due to a narrow transmissionband, if the reception terminal uses screen configuration informationwhich displays video, it has to display deteriorated video.

Furthermore, even a conventional portable type reception terminal havinga small screen such as a cellular phone terminal and PDA (Personal DataAssist) constructs a screen using the same screen configurationinformation as that of a reception terminal having a large screen suchas a notebook personal computer.

For this reason, the portable type reception terminal has a problem thatreceived data sticks out of the small screen and all the received datacannot be displayed.

On the contrary, when the reception terminal having a large screen usesthe same screen configuration information as that of the portable typereception terminal, the reception terminal displays images only in anarrow range of the large screen and cannot display the images byeffectively using the large screen.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to allow reception terminalshaving different propagation environments such as transmission bands andpacket loss rates as well as reception terminals having differentdisplay capabilities such as screen sizes to display multi-mediacontents in a screen configuration according to their propagationenvironments and display capabilities.

The present invention is constructed in such a way as to transmit aplurality of pieces of screen configuration information describing aspatial arrangement of contents from a transmission terminal and select,when a reception terminal receives the plurality of pieces of screenconfiguration information, screen configuration information according toconditions such as a transmission band and screen size of the receptionterminal and display the contents using the selected screenconfiguration information.

This allows the reception terminal to select screen configurationinformation according to the propagation environment and displaycapability and display the contents using the selected screenconfiguration information.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a description of an SMIL file;

FIG. 2 illustrates a program transmission method according to aconventional example;

FIG. 3A illustrates a cable network targeted by Embodiment 1 of thepresent invention;

FIG. 3B illustrates a network in which cable/wireless networks targetedby Embodiment 1 are mixed;

FIG. 3C illustrates a wireless network targeted by Embodiment 1;

FIG. 4 is a first diagram illustrating a data transmission/receptionsystem according to Embodiment 1;

FIG. 5 is a second diagram illustrating the data transmission/receptionsystem according to Embodiment 1;

FIG. 6 illustrates a reference example of program configurationinformation;

FIG. 7 illustrates screen configuration information according toEmbodiment 1;

FIG. 8A is a first diagram illustrating a screen displayed on a programdisplay section according to Embodiment 1;

FIG. 8B is a second diagram illustrating a screen displayed on theprogram display section according to Embodiment 1;

FIG. 9 is a third diagram illustrating a screen displayed on the programdisplay section according to Embodiment 1;

FIG. 10A is a first diagram illustrating screen configurationinformation according to Embodiment 1;

FIG. 10B is a second diagram illustrating screen configurationinformation according to Embodiment 1;

FIG. 11 illustrates program information according to Embodiment 1;

FIG. 12 is an operation flow chart of a server according to Embodiment1;

FIG. 13 is a flow chart of the operation of the reception terminalaccording to Embodiment 1;

FIG. 14 is a fourth diagram illustrating a screen displayed on theprogram display section according to Embodiment 1;

FIG. 15 is a fifth diagram illustrating a screen displayed on theprogram display section according to Embodiment 1;

FIG. 16 is a first diagram showing the configuration of a datatransmission/reception system according to Embodiment 2 of the presentinvention;

FIG. 17 is a second diagram showing the configuration of the datatransmission/reception system according to Embodiment 2 of the presentinvention;

FIG. 18 illustrates program configuration information according toEmbodiment 2;

FIG. 19 illustrates another example of the configuration informationaccording to Embodiment 2;

FIG. 20 illustrates the program configuration information indicated bydifference information according to Embodiment 2;

FIG. 21 is an operation flow chart of a server according to Embodiment2; and

FIG. 22 is a flow chart of the operation of the reception terminalaccording to Embodiment 2.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

With reference now to the attached drawings, Embodiment 1 of the presentinvention will be explained in detail below. First, the mode of use of acommunication network according to Embodiment 1 will be explained usingFIG. 3A. FIG. 3A shows an overview of a data transmission/receptionsystem according to Embodiment 1.

The present data transmission/reception system adopts a configuration inwhich servers 302 and reception terminals 304 are connected togetherthrough a communication network 301.

The reception terminals 304 are reception terminals having differentdisplay resolutions or processing capacities such as cellular phone, TV,PDA and personal computer. There are a plurality of reception terminals304.

There are also a plurality of servers 302 that distribute data and eachreception terminal 304 receives contents from a plurality of servers 302simultaneously. Furthermore, the reception terminal 304 can also have afunction of connecting a plurality of transmissions.

Communication devices such as the server 302 and reception terminal 304are mutually connected by a relay node 303 such as a router and GW(gateway). The router and GW have a broadcast or multicast function andthe router and GW can replicate data packets.

The communication network 301 may be a cable network (e.g., ADSL, ISDN,ATM, FTTH) or wireless network (e.g., cellular phone, wireless LAN).

The present data transmission/reception system uses the Internetprotocol as a transmission protocol.

Furthermore, the contents transmission method may include a one-to-onecommunication between the server 302 and reception terminal 304 orone-to-N communications using a broadcast or multicast function. In thisembodiment, the multicast function is used from the server 302 to therelay node 303 and the broadcast function is used from the relay node303 to the reception terminal.

In this way, the reception terminal 304 can receive latest contents byopening a predetermined channel.

On the other hand, the server 302 which is a transmission terminaltargets various media such as video, audio, music, text, still image,screen configuration information as contents to be transmitted.Furthermore, the server 302 transmits the program.

One program consists of contents made up of various media includingvideo, audio (including music), text, still image, animation or computergraphics, screen configuration information which controls displaypositions of the contents and program configuration information whichdescribes a combination between the screen configuration information andcontents to be displayed.

When the reception terminal 304 knows the location of the screenconfiguration information and the screen configuration informationdescribes a method of acquiring addresses of the contents to bedisplayed, the reception terminal 304 can also acquire other contents ifit acquires the screen configuration information. Therefore, the programconfiguration information is not indispensable in this case.

Furthermore, when contents are transmitted unidirectionally using amulticast or broadcast function, the method of acquiring screenconfiguration information becomes unknown, and therefore the screenconfiguration information and contents are identified using the programconfiguration information which is transmitted by a specifictransmission method.

As a description method for screen configuration information, forexample, SMIL (Synchronized Multimedia Integration Language) or JAVA(R)can be used.

Furthermore, as a description method for program configurationinformation, for example, SDP (Session Description Protocol) can beused.

Details of SMIL are described in http://www.w3.org/TR/smi120/, whiledetails of SDP are described in http://www.ietf.org/rfc/rfc2327.txt.

Here, as shown in FIG. 3B, the communication network may also be acommunication network 305 in which cable networks and wireless networksare mutually connected. Furthermore, the communication network may alsobe a broadcasting network (e.g., digital terrestrial broadcasting,digital satellite broadcasting) or a system configuration which merges abroadcasting network and communication network.

As shown in FIG. 3B, when contents are broadcast to mobile receptionterminals 307 such as cellular phones, there is also a demand forbroadcasting contents which may differ from one region to another.

In such a case, when the server 302 broadcasts or multicasts contents toa plurality of reception terminals 304, it is not easy to changebroadcasting contents according to their positions.

Therefore, in order to realize broadcasting according to positions, inthe example in FIG. 3B, a one-to-one unicast communication is realizedbetween the server 302 and relay node 306 (cable network section) andcontents are distributed between the relay node 306 and receptionterminal 307 using a broadcast function over a wireless network.

The relay node 306 which realizes the broadcast function does notbroadcast packets across other different relay nodes 306.

Furthermore, as shown in FIG. 3C, Embodiment 1 may have a communicationmode in which servers 302 are located at various positions, data arebroadcast to neighboring regions and reception terminals 307 receive thedata.

In such a communication mode, BlueTooth or wireless LAN, etc., may beused as a transmission protocol.

Next, the configuration of the transmission/reception system accordingto Embodiment 1 will be explained in detail using FIG. 4 and FIG. 5.FIG. 4 and FIG. 5 illustrate the data transmission/reception systemaccording to Embodiment 1.

The server 302 is provided with a data control section 102 that storesand controls various data.

The data control section 102 is provided with a program configurationinformation storage section 105 that stores program configurationinformation which makes up a program, a screen configuration informationstorage section 106 that stores screen configuration information, and avideo storage section 107 that stores video, a still image storagesection 108 that stores a still image and a character storage section109 that stores character data as contents storage sections. The datacontrol section 102 selects the information stored as appropriate andsends the information to a transmission control section 103.

The transmission control section 103 determines transmission sequenceand timings of the program configuration information, screenconfiguration information and contents which make up the program andsends them to the transmission section 104. Furthermore, thetransmission control section 103 generates difference information whichwill be described later and sends it to the transmission section 104.

The transmission section 104 transmits the information sent from thetransmission control section 103 to the reception terminal 304 over thecommunication network 301.

As the transmission protocol used by the server 302, it is possible touse a protocol (e.g., TCP) which confirms receipt or a protocol (e.g.,UDP) which does not confirm reception. In addition, the server 302 mayalso use a media transmission protocol represented by RTP (RealtimeTransport Protocol).

On the other hand, the reception terminal 304 is provided with areception section 202 that receives transmission from the server 302.

Furthermore, the reception terminal 304 is provided with a programconfiguration information extraction section 203 that extracts programconfiguration information from the data received by the receptionsection 202. The program configuration information extraction section203 outputs the extracted program configuration information to a screenconfiguration information selection condition extraction section 204 anda screen configuration information generation section 208.

Furthermore, the reception terminal 304 is provided with a screenconfiguration information extraction section 205 that extracts screenconfiguration information from the data received by the receptionsection 202. The screen configuration information extraction section 205outputs the extracted screen configuration information to the screenconfiguration information generation section 208.

Furthermore, the reception terminal 304 includes a contents extractionsection 206 that extracts contents such as video, audio, document, stillimage from the data received by the reception section 202. The contentsextraction section 206 outputs the extracted contents to the programdisplay control section 209.

When the program configuration information includes a screenconfiguration information selection condition, the screen configurationinformation selection condition extraction section 204 extracts thescreen configuration information selection condition from the programconfiguration information and outputs it to the screen configurationinformation generation section 208.

A terminal information acquisition section 207 acquires characteristicinformation of the reception terminal 304 and outputs it to the screenconfiguration information generation section 208.

Examples of the characteristic information of the terminal include anauthenticated transmission band of a communication channel to which theterminal is connected, effective transmission band obtained by observinga communication channel, screen size of the terminal, number ofdisplayable colors, CPU's throughput, presence/absence and capacity of astorage medium such as a semiconductor memory and magnetic disk,presence/absence of a decoder of each media such as video, audio, stillimage, etc.

The screen configuration information generation section 208 selectsscreen configuration information which matches the condition from theprogram configuration information, screen configuration information,screen configuration information extraction condition and characteristicinformation of the reception terminal 304 such as the transmission bandobtained from the terminal information acquisition section 207.Furthermore, the screen configuration information generation section 208generates new screen configuration information when the informationtransmitted is difference information which will be described later.Then, the screen configuration information generation section 208outputs the screen configuration information to the program displaycontrol section 209.

The program display control section 209 constitutes a program using thecontents extracted by the contents extraction section 206 based on thescreen configuration information transmitted and outputs the program tothe program display section 210.

Next, a reference example of the program configuration information willbe explained using FIG. 6. FIG. 6 illustrates a reference example of theprogram configuration information.

Suppose the program configuration information describes a set ofcontents of various media such as video, audio, document, still imagereproduced as program contents and screen configuration informationwhich is layout information when those contents are displayed on ascreen. FIG. 6 shows an example of program configuration informationdescribed in SDP.

The program configuration information 400 shown in FIG. 6 describesinformation on the entire program such as information on a title andadministrator on line 401 and above.

Furthermore, the program configuration information 400 describesinformation on each media on a line which starts with m= to the nextline which starts with m=.

The line (line 402) which starts with m= is information on the audiocontents and an ID “audio1” is assigned as the information identifyingthe audio contents (line 403).

Likewise, the program configuration information 400 describesinformation on the video contents (line 404, ID is “video1”),information on the document contents (line 405, ID is “text1”),information on the still image contents (line 406, ID is “image1”).

Furthermore, the program configuration information 400 describesinformation on the screen configuration information (line 407, ID is“layout1”).

From the program configuration information 400 in FIG. 6, it is evidentthat this program constitutes a screen using contents video1, audio1,text1, image1 according to the screen configuration information oflayout1.

Next, the screen configuration information transmitted by the server 302will be explained using FIG. 7. FIG. 7 illustrates screen configurationinformation transmitted by the server 302.

Suppose the screen configuration information displays positions on thescreen at which contents of various media such as video, document, stillimage reproduced as program contents are displayed. FIG. 7 shows anexample where screen configuration information is described in SMIL.

The screen configuration information 500 shown in FIG. 7 describes online 501 that the size of the entire screen is 320 dots in width and 480dots in height.

Furthermore, the screen configuration information 500 describes on line502 that a region named “video” has a size of 300 dots in width and 300dots in height at a position 100 dots down and 10 dots left from the topleft corner of the entire screen.

Furthermore, lines 503 and 504 of the screen configuration information500 also describe the positions and sizes of regions named “text” and“image.”

Furthermore, line 505 of the screen configuration information 500describes that video contents having an ID “video1” are displayed in theregion named “video” (defined on line 502).

Lines 507 and 508 of the screen configuration information 500 likewisedescribe that contents having IDs “text1” and “image1” are displayed inthe region named “text” (defined on line 503) and the region named“image” (defined on line 504).

Since line 506 describes audio contents, there is no informationindicating the region in which the contents are displayed.

The contents name “video1” is associated with ID “video1” defined online 404 in FIG. 6, the contents name “audio1” is associated with ID“audio1” defined on line 403 in FIG. 6, the contents name “text1” isassociated with ID “text1” defined on line 405 in FIG. 6 and thecontents name “image1” is associated with ID “image1” defined on line406 in FIG. 6.

In this way, the contents video1, text1 and image1 received based on theprogram configuration information 400 in FIG. 6 are layouted based onthe screen configuration information 500 in FIG. 7.

On the other hand, as shown in the program information 400 in FIG. 6,when there is only one piece of screen configuration information forconstituting one program, the following two problems occur.

1. In the case of a transmission path having a large packet loss rate ortransmission path having a small transmission band, there is a highprobability that contents having a large amount of transmission such asvideo may not be transmitted correctly and may deteriorate.

The screen displayed on the program display section 210 of the receptionterminal 304 in this case will be explained using FIG. 8.

Suppose a case where video is not received correctly in a program whichdisplays a character display area (602), a video display area (603) anda still image display area (604) on a display screen 601 as shown inFIG. 8A. In this case, as shown in FIG. 8B, the video display area 603is left blank and the amount of information displayed on the screendecreases.

2. When there is a terminal having a different screen size, the screenconfiguration may not match the size of the screen.

A screen displayed on the program display section 210 of the receptionterminal 304 will be explained using FIG. 9 in this case.

When an attempt is made to display the screen configuration informationshown in FIG. 8A on a terminal having a small screen size, part of thevideo display area (603) is lost and it is not possible to display thewhole contents as shown in FIG. 9.

Therefore, according to Embodiment 1, as a first method of solving theproblem when there is only one piece of screen configurationinformation, the transmission control section 103 of the server 302transmits a plurality of pieces of screen configuration information.That is, the transmission control section 103 of the server 302transmits screen configuration information other than the screenconfiguration information 500 shown in FIG. 7.

Next, the screen configuration information that the server 302 transmitstogether with the screen configuration information 500 shown in FIG. 7will be explained using FIG. 10. FIG. 10 illustrates screenconfiguration information according to Embodiment 1.

The screen configuration information 800 shown in FIG. 10A is differentonly in line 805 from the screen configuration information 500 shown inFIG. 7.

Line 805 shows that document contents indicated by “text2”, not videocontents are displayed in the region “video.”

That is, the reception terminal 304 selects the screen configurationinformation 800 instead of the screen configuration information 500, andcan thereby change the display contents from video contents to documentcontents of small size. This reduces the influence of deterioration ofcontents due to a packet loss.

Furthermore, the server 302 also transmits the screen configurationinformation transmitted together with the screen configurationinformation 800 shown in FIG. 10 as difference information. Next, thedifference information transmitted by the server 302 will be explainedusing FIG. 10B. FIG. 10 illustrates the difference information accordingto Embodiment 1.

The difference information which will be explained below is created bythe transmission control section 103 of the server 302 detecting thedifference with reference to a plurality of pieces of screenconfiguration information.

The difference information (“layout3”) 810 shown in FIG. 10B shows thedifference between the screen configuration information (“layout2”) 800in FIG. 10A and screen configuration information (“layout1”) 500 in FIG.7.

More specifically, “layout3” 810 shows on line 811 that “layout1” can begenerated in FIG. 7 by replacing 12th line (line 805) of “layout2” 800in FIG. 10A.

Furthermore, “layout3” 810 specifies on line 812 the portion to bereplaced of “layout2” 800 and describes on line 813 the replacingcontent.

By sending “layout3” which is the difference information between“layout1” 500 and “layout2” 800, it is substantially possible to notifytwo pieces of screen information without sending “layout1” 500.Furthermore, transmitting “layout1” 500 with “layout3” 810 which is thedifference information of “layout2” 800 can reduce an amount ofinformation of the screen configuration information transmitted.

Embodiment 1 uses an output format of a diff command of UNIX(R) as anexample of the method of expressing the difference information 810, butit is also possible to use an expression method of other differenceinformation.

Furthermore, in this embodiment, because a plurality of pieces of screeninformation are sent, the program configuration information has aplurality of pieces of screen configuration information. Furthermore,the program configuration information also describes a screenconfiguration information selection condition to select one piece ofscreen configuration information from the plurality of pieces of screenconfiguration information.

Next, the program configuration information when the server 302transmits two pieces of screen configuration information “layout2” and“layout3” will be explained using FIG. 11. FIG. 11 illustrates theprogram information according to Embodiment 1.

The program configuration information 900 shown in FIG. 11 describes online 901, line 902, line 903, line 904 and line 907 that this programtransmits “text1”, “text2”, “image1”, “layout2” and “layout3.”

Thus, the program configuration information 900 describes that theprogram has a plurality of pieces of screen configuration information ofa plurality of layouts “layout2” and “layout3.”

Furthermore, the program information 900 describes on line 905 that thescreen configuration information indicated by “layout2” is used when thetransmission band is 96000 bps or less. Line 905 of the programinformation 900 is a screen configuration information selectioncondition. It is a condition as to which of “layout2” or “layout3”should be selected.

Furthermore, line 906 of the program information 900 describes priorityin determining which screen configuration information should be selectedwhen the reception terminal 304 can select a plurality of pieces ofscreen configuration information based on the screen configurationinformation selection condition indicating a transmission band.

Line 906 of the program information 900 is also a screen configurationinformation selection condition. This is also a condition as to which of“layout2” or “layout3” should be selected.

Furthermore, line 908 of the program information 900 describes that thescreen configuration information indicated by “layout3” is differenceinformation from “layout2.” That is, in this case, “layout3” represents“layout1.” When difference information is not used as the screenconfiguration information, there is no description of line 908.

Furthermore, line 909 of the program information 900 describes that thescreen configuration information indicated by “layout3” is used when thetransmission band ranges from 64001 bps to 384000 bps.

Furthermore, line 910 of the program information 900 describes priorityof “layout3.”

Line 909 and line 910 of the program information 900 are also screenconfiguration information selection conditions.

When the reception terminal 304 can receive two pieces of screenconfiguration information “layout2” and “layout3” without any loss andcan select both “layout2” and “layout1” reconstructed from “layout3”which is the difference information under the screen configurationinformation selection condition, the reception terminal 304 selectseither one according to priority, for example, “layout3” (or “layout1”reconstructed from “layout3”) which has priority of a higher number.

Next, the operation of the server 302 transmitting the programconfiguration information, screen configuration information and contentswill be explained using FIG. 12. FIG. 12 is an operation flow chart ofthe server according to Embodiment 1.

First, the transmission control section 103 of the server 302 extractsprogram configuration information from the program configurationinformation storage section 105 of the data control section 102 (step1001).

Next, the transmission control section 103 references the extractedprogram configuration information and detects the plurality of pieces ofscreen configuration information described in the program configurationinformation (step 1002). Then, the detected screen configurationinformation is extracted from the screen configuration informationstorage section 106 (step 1003).

When the screen configuration information extracted in step 1002 isdifference information, the transmission control section 103 extractsthe difference information.

Next, the transmission control section 103 extracts contents such asvideo, still image, character described in the program informationextracted in step 1001 from the video storage section 107, still imagestorage section 108 and character storage section 109 (step 1004).

Next, the transmission control section 103 transmits the programconfiguration information extracted in step 1001 to the receptionterminal 304 through the transmission section 104 (step 1005). Next, thetransmission control section 103 transmits the screen configurationinformation described in the program configuration information extractedin step 1003 to the reception terminal 304 through the transmissionsection 104 (step 1006). Then, the transmission control section 103transmits the contents extracted in step 1004 to the reception terminal304 through the transmission section 104 (step 1007).

In this way, the server 302 transmits the program configurationinformation, a plurality of pieces of image configuration informationand contents to the reception terminal 304.

Next, the operation of the reception terminal 304 will be explainedusing FIG. 13. FIG. 13 is a flow chart of the operation of the receptionterminal 304 according to Embodiment 1.

First, the reception terminal 304 receives various types of data at thereception section 202. Next, the screen configuration informationextraction section 205 extracts a plurality of pieces of screenconfiguration information from the various types of data received andsends the screen configuration information to the screen configurationinformation generation section 208 (step 1301).

Next, when difference screen configuration information is found in thereceived screen configuration information (step 1302), the screenconfiguration information generation section 208 checks whether thereference screen configuration information corresponding to thedifference screen configuration information has been received or not(step 1303).

When FIG. 11 is taken as an example, when “layout3” has been received,it is known from line 908 that “layout3” is difference informationrelative to “layout2”, and therefore the screen configurationinformation generation section 208 checks whether “layout2” has beenreceived or not. Then, when reference screen configuration information(“layout2”) has been received, the screen configuration informationgeneration section 208 reconstructs the difference and generates screenconfiguration information (“layout1” is generated in the example of FIG.11).

Next, the screen configuration information generation section 208 usesthe condition (line 909) described in the difference information as thescreen configuration information selection condition for the screenconfiguration information generated (step 1304). The screenconfiguration information selection condition is extracted from thescreen configuration information selection condition extraction section204.

On the other hand, when the reference screen configuration informationcorresponding to the difference screen configuration information has notbeen received in step 1303, the screen configuration informationgeneration section 208 suspends or discards the difference screenconfiguration information until the reference screen configurationinformation (“layout2”) can be received (step 1305).

Next, the screen configuration information generation section 208 checkswhether the screen configuration information selection condition hasbeen received or not (step 1306).

This embodiment assumes that the screen configuration informationselection condition is included in the program configurationinformation, but the screen configuration information selectioncondition need not be described in the program configurationinformation. In this case, the screen configuration informationselection condition may be transmitted using a different transmissionmethod or need not be sent at all. When the screen configurationinformation selection condition is not sent, a screen can be configuredusing the screen configuration information which the reception terminalhas received without any loss.

When the screen configuration information selection condition has beenreceived, the screen configuration information generation section 208extracts the screen configuration information which matches thecondition (step 1307).

The program configuration information selection condition is a conditionunder which screen configuration information appropriate for thetransmission state of the reception terminal 304 is selected, andtherefore the reception terminal 304 can select the screen configurationinformation appropriate for the own terminal.

On the other hand, when the screen configuration information selectioncondition has not been received, the screen configuration informationgeneration section 208 extracts all the screen configuration informationreceived (step 1308).

Then, when there is a plurality of pieces of extracted screenconfiguration information, the screen configuration informationgeneration section 208 selects screen configuration information with thehighest priority added to the screen configuration information (step1309).

Priority is higher for screen configuration information which should bedisplayed more preferably. Therefore, since the priority information isdescribed in the screen configuration information, even when there is aplurality of pieces of screen configuration information that match thescreen configuration information selection condition according to thetransmission condition, the reception terminal 304 can select screenconfiguration information that should be displayed preferably.

Next, the screen configuration information generation section 208 sendsthe selected screen configuration information to the program displaycontrol section 209.

The program display control section 209 selects contents described inthe screen configuration information transmitted from the contentsextracted by the contents extraction section 206. Next, the programdisplay control section 209 generates a program using the screenconfiguration information transmitted and the selected contents andoutputs the program to the program display section 210 (step 1310).

Then, the program display section 210 displays the program transmitted(step 1311).

Thus, the reception terminal 304 can select screen configurationinformation appropriate for the own terminal from the plurality ofpieces of screen configuration information received, and generate anddisplay a program using the screen configuration information appropriatefor the own terminal.

For example, when the reception terminal 304 receives layout2 andlayout3 in FIG. 10 and program configuration information in FIG. 11, thereception terminal 304 can replace the portion of the video display area603 shown in FIG. 8 with the character display area 623 and displaycharacters as shown in FIG. 14.

Compared to video contents, character contents of small size also have alow probability of being lost during reception, and therefore thereception terminal 304 can accurately receive and display the charactercontents even when the transmission state is bad. Therefore, when thetransmission state is bad, the reception terminal 304 displays thecharacter contents as shown in FIG. 14 and can thereby display a greateramount of information than when displaying video with some loss (FIG.8B).

As explained above, according to Embodiment 1, the reception terminal304 can select screen configuration information according to apropagation environment and display the contents using the selectedscreen configuration information. The screen configuration informationselected according to the propagation environment is the informationusing contents that can be received by the reception terminal 304, andtherefore the reception terminal 304 can display a screen using thescreen configuration information using the contents that can bereceived.

Furthermore, Embodiment 1 is likewise applicable even when the displayscreen size of the reception terminal 304 is different. By describing“a=terminal:pc”, “a=terminal:pda” instead of “a=bandwidth: . . . ”(e.g., line 905 in FIG. 11) of the screen configuration informationselection condition, it is possible to specify screen configurationinformation for a personal computer and screen configuration informationfor a PDA. Furthermore, instead of a description indicating the type ofa terminal such as “pc” and “pda”, the screen size can be directlydescribed, for example, “a=terminal:640×480.”

The reception terminal 304 interprets these descriptions and specifiesscreen configuration information, and therefore even when the receptionterminal 304 has a small display screen 601 as shown in FIG. 15, thereception terminal 304 can select the screen configuration informationmost appropriate for the size and display the program. For example, asshown in FIG. 15, the display screen 601 can display only a character602 and still image 713 without any loss.

The embodiment has explained a mode in which a screen configurationinformation selection condition is described in program configurationinformation, but it is also possible to use a mode in which the screenconfiguration information selection condition is described in the screenconfiguration information.

In this case, for example, the screen configuration information shown inFIG. 10A or FIG. 10B can describe a screen configuration informationselection condition <condition bandwidth=“−96000“/>. More specifically,in the case of the screen configuration information shown in FIG. 10A,the screen configuration information selection condition is describedbetween </layout> and </head>.

Embodiment 1 has described contents that can be displayed on a screen,and similar output and selection are possible for audio contents, too.

For example, SMIL which is the screen configuration information used inEmbodiment 1 can also describe audio contents, and therefore it ispossible to change from screen configuration information describinglarge volume audio contents to screen configuration informationdescribing small volume audio contents. This can also prevent audiocontents to be reproduced from being lost due to a transmission state.

Here, it is also possible to adopt a mode in which processes carried outby the server 302 and reception terminal 304 are implemented by aprogram and stored in a storage medium, and a general-purpose computerreads and executes the program.

Embodiment 2

Embodiment 2 of the present invention causes a server to transmit aplurality of pieces of program configuration information as a secondmethod for solving the problem when there is only one piece of screenconfiguration information.

First, the configuration of a transmission/reception system according toEmbodiment 2 will be explained in detail using FIG. 16 and FIG. 17. FIG.16 and FIG. 17 illustrate the configuration of the datatransmission/reception system according to Embodiment 2. The same partsas those already explained are assigned the same reference numerals anddetailed explanations thereof will be omitted.

First, a server 1301 according to Embodiment 2 will be explained.

A transmission control section 1302 of the server 1301 extracts aplurality of pieces of program configuration information 105 andtransmits them to a reception terminal 1303 according to Embodiment 2through a transmission section 104.

Furthermore, when transmitting a plurality of pieces of programconfiguration information, the transmission control section 1302 alsouses difference program information which is difference informationamong them. Furthermore, the transmission control section 1302 detectsthe difference from the plurality of pieces of program information andgenerates difference program information.

Next, the configuration of the reception terminal 1303 will beexplained.

The reception terminal 1303 is provided with a program configurationinformation selection condition extraction section 1404 that extracts aprogram configuration information selection condition when the programconfiguration information selection condition is included in the programconfiguration information output from a program configurationinformation extraction section 203. The program configurationinformation selection condition extraction section 1404 outputs theextracted program configuration information selection condition to aprogram configuration information generation section 1408.

The program configuration information generation section 1408 selectsprogram configuration information that matches the program configurationinformation extraction condition from information on a transmissionband, etc., obtained from a terminal information acquisition section207. When the program configuration information is described withdifference information from other program configuration information, theprogram configuration information generation section 1408 also generatesnew program configuration information. The program configurationinformation generation section 1408 transmits the program configurationinformation obtained to a screen configuration information extractionsection 1409.

The screen configuration information extraction section 1409 extractsthe screen configuration information described in the received programconfiguration information and sends it to a program display controlsection 209.

Next, the program configuration information transmitted by the server1301 will be explained using FIG. 18. FIG. 18 illustrates the programconfiguration information according to Embodiment 2.

Line 1001 of the program configuration information 1600 of Embodiment 2describes a name “program1.”

Furthermore, line 1002 of the program configuration information 1600describes that this program configuration information is used when thetransmission band ranges from 64001 bps to 384000 bps. The descriptionon this line 1002 is a program configuration information selectioncondition.

Thus, Embodiment 2 causes the server 1301 to transmit a plurality ofpieces of program configuration information, and therefore the programconfiguration information is assigned a program configurationinformation selection condition so that the reception terminal 1303 canselect appropriate program configuration information.

Furthermore, line 1003 of the program configuration information 1600describes priority for deciding which program configuration informationshould be selected when the reception terminal 1303 can select aplurality of pieces of program configuration information under theprogram configuration information selection condition (line 1002)indicating the transmission band.

Furthermore, line 1003 of the program configuration information 1600 isalso called a “program configuration information selection condition.”

Furthermore, lines 1004 to 1008 of the program information 1600 describethat this program consists of “audio1”, “video1”, “text1”, “image1” andscreen configuration information “layout1.”

Another example of the program configuration information according toEmbodiment 2 will be explained using FIG. 19. FIG. 19 illustratesanother example of the program configuration information according toEmbodiment 2.

Line 1101 of a program configuration information 1700 shown in FIG. 19has a name “program2.”

Furthermore, line 1102 of the program configuration information 1700describes that this program information is used when the transmissionband is equal to or lower than 96000 bps as the program configurationinformation selection condition.

Furthermore, line 1103 of the program configuration information 1700describes that priority is 3. This embodiment assumes that a greatervalue in priority indicates higher priority.

Furthermore, lines 1104 to line 1107 of the program configurationinformation 1700 describe that this program consists of “text1”,“text2”, “image1” and screen configuration information “layout2.”

The server 1301 transmits the program configuration information“program1“1600 and “program2” 1700 to which a program informationselection condition is assigned.

Furthermore, the server 1301 may transmit difference information asprogram configuration information.

The program configuration information (difference program configurationinformation) indicated by difference information will be explained usingFIG. 20. FIG. 20 illustrates the program configuration information whichis difference information according to Embodiment 2.

The difference program configuration information uses an output formatof a diff command of UNIX(R) in the same way as the difference screenconfiguration information of Embodiment 1.

Line 1201 of difference program configuration information 1800 shown inFIG. 20 describes a name “program3.”

Furthermore, line 1202 of the difference program configurationinformation 1800 describes that this program configuration informationis difference information from the program configuration informationindicated by “program2.”

Furthermore, line 1203 of the difference program configurationinformation 1800 describes that this program configuration informationis used when the transmission band ranges from 64001 bps to 384000 bps(program configuration information selection condition).

Furthermore, line 1204 of the difference program configurationinformation 1800 describes that priority is 4 (program configurationinformation selection condition).

Furthermore, line 1205 and line 1206 of the difference programconfiguration information 1800 describe that contents “audio1”, “video1”are added to “program2.”

Furthermore, line 1207 of the difference program configurationinformation 1800 describes that “text2” is deleted from “program2.”

Furthermore, line 1208 and line 1209 of the difference programconfiguration information 1800 describe that screen configurationinformation“layout1” is added and “layout2” is deleted.

The server 1301 may also be adapted so as to transmit programconfiguration information “program2” and difference program information“program3.” This allows the server 1301 to reduce the amount ofinformation of a plurality of pieces of program configurationinformation transmitted to the reception terminal 1303.

Next, the operation of the server 1301 transmitting programconfiguration information, screen configuration information and contentswill be explained using FIG. 21. FIG. 21 is an operation flow chart ofthe server according to Embodiment 2.

First, the transmission control section 1302 of the server 1301 extractsthe program configuration information from a program configurationinformation storage section 105 of a data control section 102 (step1901).

Next, the transmission control section 1302 references the extractedprogram configuration information and detects the screen configurationinformation described in the program configuration information (step1902). Then, the transmission control section 1302 extracts the detectedscreen configuration information from a screen configuration informationstorage section 106 (step 1903).

Next, the transmission control section 1302 extracts contents such asvideo, still image, character described in the program informationextracted in step 1901 from a video storage section 107, still imagestorage section 108 and character storage section 109 (step 1904).

Next, the transmission control section 1302 transmits the programconfiguration information extracted in step 1901 to the receptionterminal 1303 through the transmission section 104 (step 1905). Next,the transmission control section 1302 transmits the screen configurationinformation described in the program configuration information extractedin step 1903 to the reception terminal 1303 through the transmissionsection 104 (step 1906). Then, the transmission control section 1302transmits the contents extracted in step 1904 to the reception terminal1303 through the transmission section 104 (step 1907).

Then, the transmission control section 1302 carries out processes instep 1901 to step 1907 on all program configuration information to betransmitted (step 1908).

When the program configuration information extracted in step 1901 isdifference information, the transmission control section 1302 extractsthe difference program information.

In this way, the server 1301 transmits a plurality of pieces of programconfiguration information, image configuration information described inthem and contents to the reception terminal 1303.

Next, the operation of the reception terminal 1303 according toEmbodiment 2 will be explained using FIG. 22. FIG. 22 is a flow chart ofthe operation of the reception terminal 1303 according to Embodiment 2.

First, the reception terminal 1303 receives various types of data at areception section 202. Next, the program configuration informationextraction section 203 extracts a plurality of pieces of programconfiguration information from the received various types of data andsends them to the program configuration information generation section1408 (step 1501).

Next, when the program configuration information generation section 1408discovers difference program configuration information in the pluralityof pieces of program configuration information transmitted (step 1502),the program configuration information generation section 1408 checkswhether the reference program configuration information corresponding tothe difference program configuration information has been received ornot (step 1503).

Taking FIG. 20 as an example, when “program3” has been received, it isknown from line 1202 that “program3” is difference information relativeto “program2”, and therefore the program configuration informationgeneration section 1408 checks whether “program2” has been received ornot.

When the reference program configuration information (“program2”) hasbeen received, the program configuration information generation section1408 reconstructs the difference and generates program configurationinformation (“program1” is generated in the example in FIG. 20).

Next, the program configuration information generation section 1408 usesthe condition (line 1203) described in the difference information as theprogram configuration information selection condition for the programconfiguration information generated (step 1504). The programconfiguration information selection condition is extracted by theprogram configuration information condition extraction section 1404.

On the other hand, when the reference program configuration informationcorresponding to the difference program configuration information hasnot been received, the program configuration information generationsection 1408 suspends or discards the difference program configurationinformation until the reference program configuration information(“program2”) can be received (step 1505).

Next, the program configuration information generation section 1408checks whether the program configuration information selection conditionhas been received or not (step 1506).

Embodiment 2 assumes that the program configuration informationselection condition is included in the program configurationinformation, but the program configuration information selectioncondition need not be described in the program configurationinformation. In this case, the program configuration informationselection condition may be transmitted using a different transmissionmethod or may not be transmitted at all. When it is not transmitted, theprogram may be configured using the program configuration informationwhich the reception terminal has received without any loss.

Next, when the program configuration information selection condition hasbeen received, the program configuration information generation section1408 extracts the program configuration information that matches thecondition (step 1507).

Since the program configuration information selection conditionindicates the transmission condition of the reception terminal 1303,this allows the reception terminal 1303 to select program configurationinformation appropriate for the transmission condition.

Furthermore, when the program configuration information selectioncondition has not been received, the program configuration informationgeneration section 1408 extracts all the received program configurationinformation (step 1508).

When there is a plurality of pieces of extracted program configurationinformation, the program configuration information generation section1408 selects the program configuration information having the highestpriority added (step 1509).

Priority is higher for information which should be displayed morepreferably. The program configuration information describes priorityinformation, and therefore even when there are a plurality of pieces ofprogram configuration information that match the program configurationinformation selection condition under the transmission condition, thereception terminal 1303 can select program configuration informationwhich should be displayed preferably.

Next, the program configuration information generation section 1408sends the selected program configuration information to the screenconfiguration information extraction section 1409.

The screen configuration information extraction section 1409 extractsthe screen configuration information described in the programconfiguration information transmitted and sends it to the programdisplay control section 209 (step 1510).

Next, the program display control section 209 selects contents describedin the screen configuration information transmitted from the contentsextracted by the contents extraction section 206. Next, the programdisplay control section 209 generates a program using the screenconfiguration information transmitted and selected contents and outputsthe program to a program display section 210 (step 1511).

Then, the program display section 210 displays the program transmitted(step 1512).

In this way, the reception terminal 1303 selects program configurationinformation appropriate for the own terminal from the plurality ofpieces of program configuration information received and can generateand display a program using the program configuration informationappropriate for the own terminal.

In Embodiment 2, when the reception terminal 1303 receives layout2,layout3 in FIG. 10 and program configuration information in FIG. 11, itis possible to replace the portion of the video display area 613 shownin FIG. 8 by the character display area 623 and display characters asshown in FIG. 14.

Furthermore, Embodiment 2 is likewise applicable when the display screensize of the reception terminal 1303 is different. By describing“a=terminal:pc”, “a=terminal:pda” instead of “a=bandwidth: . . .” (e.g.,line 1002 in FIG. 18) of the program configuration information selectioncondition, it is possible to specify the screen configurationinformation for a personal computer, screen configuration informationfor a PDA. Furthermore, instead of the description such as “pc” and“pda” indicating the type of terminal, it is also possible to directlydescribe the screen size, for example, as “a=terminal: 640×480.”

The reception terminal 1303 interprets these descriptions and specifiesprogram configuration information, and even when the reception terminal1303 has a small display screen 601 as shown in FIG. 15, it is possibleto select screen configuration information appropriate for the size anddisplay the program.

It is also possible to implement the processes carried out by the server1301 and reception terminal 1303 by a program, store the program in astorage medium and cause a general-purpose computer to read and executethis program.

This application is based on the Japanese Patent Application No.2003-065670 filed on Mar. 11, 2003, entire content of which is expresslyincorporated by reference herein.

INDUSTRIAL APPLICABILITY

As described above, even when a transmission band varies from onereception terminal to another and in a transmission environment such asbroadcasting in which the type of contents that can be received alsovaries, it is possible to display deteriorated contents and prevent anamount of information displayed from reducing by changing screenconfiguration information so that only contents that can be displayedare displayed according to the transmission band.

Furthermore, by changing screen configuration information according tothe size of the screen of the reception terminal, it is possible tospecify and display screen configuration information that matches thescreen size and obtain the effect of avoiding the problem that thecontents stick out of a small screen and the whole contents cannot bedisplayed or that contents can only be displayed within a small range ona large screen.

1. A transmission apparatus comprising: a contents storage section thatstores contents; a screen configuration information storage section thatstores a plurality of pieces of screen configuration informationdescribing a screen arrangement of said contents; a control section thatextracts said contents and said plurality of pieces of screenconfiguration information; and a transmission section that transmitssaid contents extracted and a plurality of pieces of screenconfiguration information extracted, wherein said control sectiontransmits a selection condition for selecting one piece of said screenconfiguration information from said plurality of pieces of screenconfiguration information.
 2. The transmission apparatus according toclaim 1, wherein said selection condition is described in said screenconfiguration information.
 3. The transmission apparatus according toclaim 1, wherein said plurality of pieces of screen configurationinformation include reference screen configuration information anddifference screen configuration information which is a difference fromsaid reference screen configuration information.
 4. The transmissionapparatus according to claim 1, wherein said selection condition is atleast one of a transmission band, type of a terminal of a transmissiondestination and capability of the terminal of the transmissiondestination.
 5. The transmission apparatus according to claim 1, whereinsaid selection condition is priority information.
 6. The transmissionapparatus according to claim 1, further comprising a programconfiguration information storage section that stores a plurality ofpieces of program configuration information describing said contents,said screen configuration information and a selection condition forselecting one piece of said screen configuration information from saidscreen configuration information, wherein said control section extractsa plurality of pieces of said program configuration information, detectssaid contents and said screen configuration information described insaid plurality of pieces of program configuration information extracted,extracts said contents and screen configuration information detected,and said transmission section transmits said plurality of pieces ofprogram configuration information extracted, said contents and screenconfiguration information.
 7. The transmission apparatus according toclaim 6, wherein said plurality of pieces of program configurationinformation includes said reference program configuration informationand difference program configuration information which is a differencefrom said reference program configuration information.
 8. Thetransmission apparatus according to claim 6, wherein said selectioncondition is at least one of a transmission band, type of a terminal ofa transmission destination and capability of the terminal of thetransmission destination.
 9. The transmission apparatus according toclaim 6, wherein said selection condition is priority information.
 10. Areception apparatus comprising: a reception section that receivescontents, one or more pieces of screen configuration informationdescribing a screen arrangement of said contents and a selectioncondition for selecting one piece of said screen configurationinformation from said one or more pieces of screen configurationinformation; a screen configuration information selection section thatselects one piece of said screen configuration information from saidplurality of pieces of screen configuration information based on saidselection condition; a screen generation section that generates a screenfrom said screen configuration information selected and said contents;and a display section that displays said screen generated.
 11. Thereception apparatus according to claim 10, wherein said plurality ofpieces of screen configuration information received include saidreference screen configuration information and difference screenconfiguration information which is a difference from said referencescreen configuration information, when said difference screenconfiguration information is selected, said screen generation sectionnewly generates said screen configuration information from saidreference screen configuration information and said difference screenconfiguration information and generates a screen from said screenconfiguration information generated and said contents which make up saidscreen configuration information generated.
 12. The reception apparatusaccording to claim 10, wherein said selection condition is at least oneof a transmission band, type of a terminal and capability of theterminal.
 13. The reception apparatus according to claim 12, furthercomprising a terminal information acquisition section that observes aneffective transmission band of said reception section, wherein saidselection condition is the transmission band observed by said terminalinformation acquisition section.
 14. The reception apparatus accordingto claim 10, wherein said selection condition is priority information.15. The reception apparatus according to claim 10, wherein saidreception section receives a plurality of pieces of programconfiguration information describing said contents, said screenconfiguration information and selection condition, said receptionsection further comprising: a program configuration informationselection section that selects one piece of said program configurationinformation from said plurality of pieces of program configurationinformation based on said selection condition described in saidplurality of pieces of program configuration information; a programgeneration section that generates a screen from said contents and saidscreen configuration information making up said program configurationinformation selected; and a display section that displays said screengenerated.
 16. The reception apparatus according to claim 15, whereinsaid plurality of pieces of program configuration information receivedinclude said reference program configuration information and differenceprogram configuration information which is a difference from saidreference program configuration information, when said differenceprogram configuration information is selected, said program generationsection newly generates said program configuration information from saidreference program configuration information and said difference programconfiguration information and generates a screen from said programconfiguration information generated, said contents and said screenconfiguration information making up said program configurationinformation generated.
 17. The reception apparatus according to claim15, wherein said selection condition is at least one of a transmissionband, type of a terminal and capability of the terminal.
 18. Thereception apparatus according to claim 15, wherein said selectioncondition is priority information.
 19. A data transmission/receptionsystem comprising: a transmission apparatus comprising a contentsstorage section that stores contents, a screen configuration informationstorage section that stores a plurality of pieces of screenconfiguration information describing a screen arrangement of saidcontents, a control section that extracts said contents and saidplurality of pieces of screen configuration information and atransmission section that transmits said contents extracted and aplurality of pieces of screen configuration information extracted,wherein said control section transmits a selection condition forselecting one piece of said screen configuration information from saidplurality of pieces of screen configuration information; and a receptionapparatus comprising a reception section that receives said contents,one or more pieces of said screen configuration information and aselection condition for selecting one piece of said screen configurationinformation from said one or more pieces of screen configurationinformation, a screen configuration information selection section thatselects one piece of said screen configuration information from saidplurality of pieces of screen configuration information based on saidselection condition, a screen generation section that generates a screenfrom said screen configuration information selected and said contentsand a display section that displays said screen generated.
 20. Atransmission method comprising the steps of: transmitting contents;transmitting a plurality of pieces of screen configuration informationdescribing a screen arrangement of said contents; and transmitting ascreen configuration information selection condition for selecting onepiece of screen configuration information from said plurality of piecesof screen configuration information.
 21. A contents browsing methodcomprising the steps of: receiving contents; receiving a plurality ofpieces of screen configuration information describing a screenarrangement of said contents; receiving a screen configurationinformation selection condition for selecting one piece of screenconfiguration information from said plurality of pieces of screenconfiguration information; selecting one piece of said screenconfiguration information based on said screen configuration informationselection condition; generating a screen from said screen configurationinformation selected and said contents making up said selected screenconfiguration information; and displaying said screen generated.
 22. Acontents browsing method comprising: the steps on the transmitting sideof transmitting contents, transmitting a plurality of pieces of screenconfiguration information describing a screen arrangement of saidcontents and transmitting a screen configuration information selectioncondition for selecting one piece of screen configuration informationfrom said plurality of pieces of screen configuration information; andthe steps on the receiving side of receiving said contents, receivingsaid plurality of pieces of screen configuration information, receivingsaid screen configuration information selection condition, selecting onepiece of said screen configuration information based on said screenconfiguration information selection condition, generating a screen fromsaid screen configuration information selected and said contents anddisplaying said screen generated.
 23. A program that causes a computerto execute the steps of: transmitting contents; transmitting a pluralityof pieces of screen configuration information describing a screenarrangement of said contents; and transmitting a screen configurationinformation selection condition for selecting one piece of screenconfiguration information from said plurality of pieces of screenconfiguration information.
 24. A program that causes a computer toexecute the steps of: receiving contents; receiving a plurality ofpieces of screen configuration information describing a screenarrangement of said contents; receiving a screen configurationinformation selection condition for selecting one piece of screenconfiguration information from said plurality of pieces of screenconfiguration information; selecting one piece of said screenconfiguration information based on said screen configuration informationselection condition; generating a screen from said screen configurationinformation selected and said contents making up said selected screenconfiguration information; and displaying said screen generated.
 25. Astorage medium that stores the program according to claim
 23. 26. Astorage medium that stores the program according to claim 24.